


The Jean Complex

by TransBoyFanBoy



Series: Humanity’s Brightest Series [7]
Category: Shingeki no Kyojin | Attack on Titan
Genre: Age Regression/De-Aging, Baby!Jean, Caregiver!Marco, Fluff, M/M, Marco Bott is a Sweetheart, Non-Sexual Age Play, Non-Sexual Intimacy
Language: English
Status: Completed
Published: 2019-11-26
Updated: 2019-11-26
Packaged: 2021-02-25 02:27:07
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,125
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21569281
Author URL: https://archiveofourown.org/users/TransBoyFanBoy/pseuds/TransBoyFanBoy
Summary: It had been one month since Marco had babysat Eren after the boy had sprained his ankle, and he couldn't stop thinking about how good it felt to be needed.In which Marco wants to feel needed and Jean needs to be taken care of.
Relationships: Levi & Eren Yeager, Marco Bott/Jean Kirstein
Series: Humanity’s Brightest Series [7]
Series URL: https://archiveofourown.org/series/735654
Comments: 5
Kudos: 83





	The Jean Complex

One month.

It had been one month since Marco had babysat Eren after the boy had sprained his ankle, and he couldn't stop thinking about how good it felt to be needed.

Marco had wandered back to his room that night in a sort of haze, thinking of how complete he felt holding someone in his arms and showering them with affection. His mind continued to be occupied by these thoughts as he laid in bed that night, and he drifted into a peaceful slumber. However, the experience followed him into his dreams that night. He replayed the scene in his sleep, and he let his unconscious mind become dominated by the joy he felt caring for someone. Every detail of the previous day replicated in his subconscious exactly, except one: the baby.

In the midst of his dream, he noticed one particular change to the scene he remembered. Rather than the "baby" being Eren, the face and body morphed into the object of Marco's own affections: Jean.

Marco awoke with a start, sitting up in his bunk and running a hand through his hair. He scrubbed the other hand down his freckled face as he lingered on the feelings the dream left him with. He had felt content, useful, and relaxed. Now, though, a tinge of anxiety mixed in with those feelings. Marco had no clue how to broach the topic of regression with Jean. He wasn't sure his partner would even consider the idea before laughing in his face and rejecting it.

However, he reminded himself of Levi's wise words.

_"If this is truly something you want, then you need to talk to your partner about it. If it doesn't go well, then there's not much you can do, but you'll never know if you don't go for it."_

Marco smiled to himself and laid back in bed. He would worry about the inevitable conversation with Jean later. For now, he would catch up on some much-appreciated sleep.

——————————————

The following day, they were given the rare privilege of a day off, so long as they stayed on base. Marco couldn't have been happier as he made his way to the mess hall for breakfast. He was met with the peculiar sight of each of his friends in a good mood. Everyone was smiling and joking with one another, and he beamed as he say down with his tray.

"It's so cool of them to give us a day off!" Armin cried joyously to the group.

"Tell me about it; I thought we'd never get a repreive from Levi's cold, dead eyes." Someone else exclaimed. Eren jumped to Levi's defense.

"Come on, guys, he's not that bad. He's lightened up recently, hasn't he?" Everyone else at the table mumbled disagreements and comtinued to eat their food.

Marco glanced over and noticed that one person had been unusually silent in the morning's conversation. Jean sat there, picking at his plate, and looking forlornly down at the table. His body was tensed in a way that couldn't be comfortable, and he radiated a gloomy, exhausted presence. Marco frowned at that for a moment before planting a small smile on his face and tapping Jean's foot with his own under the table. Jean looked up.

"The food isn't going to eat itself, Jean, no matter how much you poke at it." Jean let out a halfhearted chuckle at that and met his partner's eyes.

"I haven't really been in the mood for food lately." Marco frowned once again, and his worry for Jean increased tenfold.

"Would you at least try to eat something? If not for you, to put me at ease, at least?" Jean grumbled something under his breath, but nonetheless he lifted the fork to his mouth and took a small bite out of his breakfast.

_Anything for Marco._

—————————————

As a few days passed, Marco noticed that Jean's state didn't seem to be improving. Perhaps this is what finally gave him the courage to broach the topic of regression with his boyfriend. He walked into the quarters to find it empty besides Jean, who laid in bed, reading some novel Marco had never heard of.

He steeled himself as he walked over to his boyfriend's bed and sat at the end of it.

"Jean, can I talk to you about something? It's important." Jean's head snapped up at the words and he immediately began to suspect the worst.

"Did I do something wrong, Marco? I know I've been weird lately, but I swear I wasn't trying to hurt you or push you away! I can try to do better, Marco, just please don't say what I think you're going to—" Marco's eyes widened and he quickly backtracked, shaking his hands and taking hold of Jean's slightly shaky ones.

Jean had tears in his eyes as Marco rubbed his hands with his thumbs.

"No, Jean, it's okay! I'm not breaking things off between us at all, so you don't have to worry about that. It is about how you've been acting recently, but it's nothing bad, alright? Do you trust me?" Jean's hands ceased their shaking, and he nodded minutely as he met Marco's gentle gaze.

"I trust you, Marco."

Marco smiled and scooted closer to Jean on the bed, pulling him into his side and pressing a soft kiss to the man's head. After a few moments for Jean to calm down, Marco pulled back and looked him in the eyes, holding onto his hands again.

"As you know, you've been acting strage lately. You're becoming more stressed and upset as the days go by, and I can't sit here and let you go through that alone without at least offering my help to you. Now, I'm going to suggest something that you may not like, but I would greatly appreciate if you would hear me out and not voice any complaints until I'm done talking. Okay?" Jean nodded at Marco's words.

"I think that I know of something that will help you destress and deal with the things we experience—a coping mechanism, if you will." Jean quietly nodded, not meeting his boyfriend's eyes.

"What is it?"

"Have you ever heard of age regression, Jean?" The brunette shook his head and drew his brows together.

"No, why? What is it?" Marco sighed, somewhat relieved that he wouldn't have any preconceived notions about age regression. He quickly explained.

"Age regression is where an adult reverts their mind back to a time in which there was no stress—in most cases to cope with anxiety, depression, and trauma they've experienced in their lives. In other words, the age regressor, or the person in question, essentially feels, acts, and speaks like a child, toddler, or baby. Of course, there are some cases in which a person will revert to teen years and there are people who do this for leisure, but for your case, I'd say it would be more likened to the trauma aspect."

"So... you want me to act like a kid to help me with my stress?" Jean was outwardly confused, but he kept an open mind as Marco continued to speak.

"Essentially, that is what I'm suggesting. However, it's not really acting. Age regressors have a whole mindset detached from their normal, adult one, that they go into when they regress. Some people call it a headspace, but in this state of mind, the regressor feels like a child, and so they exhibit the same patterns of speech and behavior as a child would. Oh! And many age regressors also have people designated to take care of them and watch over them when they're feeling small. These are called caregivers. What I'm suggesting, if you're willing, is that I would be your caregiver and you would be the age regressor." Marco paused and looked to Jean to gauge his reaction. He was pleasantly surprised to find that his partner was trying to take in all of the imformation seriously.

"It sounds embarrassing... could you tell me a little more about it so I'm not making a decision off of just that?" Marco beams proudly and continues to speak.

"Of course! Thank you for considering it, Jean, I appreciate that. Anyways, age regressors usually have supplies to help them stay in the small mindset, such as pacifiers, coloring and story books, bottles, sippy cups, diapers, and stuffed animals. These help keep the regressor grounded in that headspace so that they can be comfortable. Let's see, what else... in headspace, if I were to be your caregiver, I'd mostly be concerned with making sure you were happy, safe, and had everything you needed. My goal would be to get you into headspace and keep you there for as long as you wished, and when you were feeling like "adult Jean" again, we would go back to being boyfriends and nothing would change. I'd just be there to provide you with anything you'd like to keep you stress-free." Jean smiled shyly and looked down, thinking about how lucky he must be to have someone as thoughtful and caring as Marco in his life.

"It definitely sounds like you've given this a lot of thought, huh? Where did you even hear about this?" Marco nodded.

"I have, yes. A friend of mine is an age regressor and I've babysat while their caregiver was busy. If I'm being honest, I really would like to try this out. I feel like it would help me feel needed and useful and _relaxed_ in a way I can't be on a regular basis. You know I love taking care of people and I'm great with kids. I just find the idea really appealing. But of course, we're only going to enter into this if you genuinely want to try it out, okay? I'm not going to pressure you into it or make you feel guilty if you decide this isn't what you want, alright?" Jean scooted closer to Marco this time and hugged him tightly.

"I love you, Marco. You always look out for me... and, I'd be willing to try it out with you, if you think it would benefit both of us. I trust you, Marco. I'll do it." Marco beamed proudly at Jean and pressed a chaste kiss to his lips.

"Okay, Jean, I promise you won't regret this. I love you too, honey."

 _'Yes,'_ Jean thought, _'I would do anything for Marco.'_

————————————

It was around two weeks later when Marco first attempted to help Jean regress. After a few more conversations about how the shift in their dynamic would go, Marco and Jean had finally felt like they were both ready to try it out.

Marco and Jean had finished dinner incredibly early one evening, and Marco knew that they would have around an hour and a half before the rest of the troops came ambling in to get ready for bed. Marco led Jean to his own bed, under which there was a duffel bag of Marco's clothes. He pulled the bag out from under the bed and placed it between the two of them; he unzipped the main compartment and pulled out one of his sleep shirts. He handed it to Jean.

"Here, put this on." Jean's eyebrows pinched in confusion.

"Why?"

"Because I think it would look cute on you, sweetheart." Jean tilted his head but exchanged his shirt for Marco's nonetheless. He cuddled into the shirt and found comfort in finding Marco's scent all over it. He smiled lightly.

"What was the point of this?" Jean asked again.

"I just wanted you to be comfortable, little guy." Jean's eyes widened at Marco's words, and his face engulfed itself in heat.

"Marco, what—now?" Marco laid a kiss on Jean's pink cheek, nodding solemnly.

"I thought right now would be alright to try it, if that's okay with you?" Jean stared over at Marco for a few moments before nodding shyly.

"Yeah, alright."

"Okay, good. Now come here, baby." Marco opened his arms for Jean to crawl into, moving the duffel bag aside as he straddled Marco's lap and buried his face in his boyfriend's shoulder. Marco rocked them back and forth for a few moments, and Jean felt somewhat different. He still felt like himself, but there was some new feeling beginning to creep up. He couldn't relax into it.

Marco spoke softly after a few minutes.

"It's okay if you don't quite feel small this time, sweetheart. These things can take time, and I'm not going anywhere as long as I can help it." Jean blushed again and nuzzled his face further into Marco's shoulder, feeling an odd mixture of safe and insecure—vulnerable, he should say.

"You don't worry about a thing, Jean. We're going at your pace." Jean nodded slightly and closed his eyes.

He felt something, just slightly out of reach. He sighed quietly and slumped into his boyfriend, letting himself doze off like that.

Marco continued to rock him and pet his hair until the others came in, relishing in the joys of being complete.

———————————

The next two times they tried to get Jean to age down went relatively similarly, and Jean could feel himself on the cusp of this "headspace". His mind got fuzzy around the edges, and he felt a needy part of him tugging at him, trying to fight to the surface. Something in him kept him from letting go. Most probably, it was the idea that had been ingrained into him simce childhood, the part of his brain that told him he needed to be strong, vigilant.

He wanted to let go of all of the worries and let Marco care for him like he promised. He wanted to curl up with his partner and cuddle him, all of his insecurities falling away with each new tick of the clock. Most importantly, he wanted to let go so that he could see more of Marco's proud face shining towards him when he realized that Jean had finally been able to drop.

Marco wanted all of this, too, but he was perfectly content just cuddling his boy and letting him know that he would be right there for him through it all.

Finally, after about a month of frequent efforts to help Jean feel small, something clicked.

It had been a long day, and everyone was exhausted. The day had taken a particular toll on Jean, who had already been in a precarious mental state. Tears came to his eyes as he and Marco walked back to the barracks. He sniffled unintentionally.

Marco looked over with concern and stopped the two of them from walking when he noticed a tear run down Jean's face. He wiped it away with a thumb and cradled Jean's face in his hand.

"Oh, Jean. I know today was a hard day, wasn't it? How about we go back to the bunker and you let me get you cleaned up, hmm? Let me take care of you tonight, Button."

_Button._

That was when it clicked. Jean let out a small sob and fell into Marco's chest, clutching his shirt and mumbling nonsense into the fabric. Marco shushed him and pet his hair, trying to calm him enough to get him to make it back to the barracks. No dice. The boy in his arms only seemed to cry harder as time went on, and Marco was struggling to figure out a way to get him back that didn't involve all of their friends witnessing Jean wailing like a toddler into his clothes.

As if by some miracle, Levi wandered onto the field with Erwin. The two made their way towards the loudly crying boy, and stopped in front of the couple. Levi's face changed only slightly from the usual stoic expression as he tilted his head towards the pair.

"What's wrong with Kirstein?" The raven-haired man asked.

Marco looked up at Erwin then back at Levi, hesitant to answer. Sure, his partner seemed far too out of it to notice and Levi had the same dynamic with Eren, but would Jean really want him to tell their Captain about this? And what about Erwin? Did he even know about this type of thing?

Before he could get too deep into his musings, Jean choked out a single word that made his heart both swell and fill with anxiety simultaneously.

"P-Papa."

Marco was quick to react, lifting the boy into his arms and holding with with minimal difficulty. Jean wrapped himself around Marco as he stuck his thumb in his mouth for comfort. He hid his face away from the other three men watching him, and he let out a little whimper. Marco stroked his hair and whispered comfortingly to the boy in his arms. Jean spoke again quietly.

"Home, Papa."

Levi and Erwin watched the scene with raised brows and wide eyes. They snapped into action as well, guiding the pair to the building and past the troops' room. They were led into the hallway that held Eren's nursery, and then they were taken to a spare, single-person spare room.

The room itself was nothing special, but it did afford the four men the privacy that one doesn't get with a communal bedroom and restroom. There was a small en-suite through one door, and a full-sized bed pressed up against the far wall. Marco crossed the room and went to place the regressed boy down onto the bed, but Jean only whined and held tighter, the waterworks that had temporarily subsided threatening to restart. Marco sat on the edge of the bed and let his boy get comfortable in his lap.

Marco saw the thumb-sucking and although it was adorable, he knew that it probably not the most sanitary thing for the boy to be doing. He looked up at Levi and Erwin pleadingly.

"Would you two mind going to get my duffel bag from the main room? It's under my bed, and I have all of my clothes and some of the supplies he'll need in it." They nodded and Levi sent Erwin out of the room to get it.

Alone besides the baby in Marco's arms, Levi spoke into the quiet room.

"So you took my advice, I see. How long has this been going on?" Levi gestured to the couple. Marco rubbed the back of his neck with the hand that wasn't supporting Jean's back.

"Not long, really—make a month or so. This is actually his first time fully regressing. We've been working on getting him comfortable enough and trying to regress for about a month, and I guess the stress of the day coupled with my slight coaxing finally worked. I'm really proud of him, honestly." Marco turned his attention to the boy in his lap, who was suckling on his thumb contently and staring up at Marco.

"Yes, Button, I'm so proud of you! You did it! Such a good, tiny boy aren't you?" Jean wiggled happily in his lap at the cooing, and reached to touch Marco's face.

Marco was enamored, and he and Levi were fawning over the adorable boy when Erwin came back in with the duffel bag. The man set the bag down on the bed next to Marco, giving Jean a smile.

"Thank you, Commander Erwin." The older man nodded.

"So how young would you say he is, Levi? Surely he's no older than two at the moment." Erwin spoke up.

"From my experience with Eren, I'd put him at about a year. He's almost completely nonverbal, very clingy, and he's got that look about him that only comes from babyspace. What supplies do you have, Marco?" Marco caressed his baby's hair as he recalled the items in the duffel.

"I bought him a pacifier, a sippy cup, a bottle, a stuffed animal, a blankie, and a couple of toys for different age ranges in case he wasn't one specific age. I couldn't fit much more in the bag on top of my clothes." Levi hummed at Marco's words.

"It seems like you've got a decent start. However, if he's going to stay in babyspace, you may need to be a bit more prepared for accidents and the "mock-teething" phase. If you'd like, I could lend you one of Eren's unused teethers and give you a couple of diapers or pull-ups. I'm not sure if you've discussed this stuff with him yet, but I've got you covered if you need it." Marco smiled at his Captain's willingness to help him out.

"We have talked about it a lot, actually, and he said he's okay to go as far as necessary, although he was incredibly embarrassed admitting it. We trust one another, don't we, baby?" Marco shifted his focus to the little one in his lap, speaking softly and adoringly to him. Jean giggled and nodded, pressing his face into Marco's chest again.

"If it would be okay with you, could you get me the diapering supplies from Eren's nursery and let me change him privately? I know he's going to be embarrassed enough as it is, but I don't want to upset more than necessary."

"Of course, kid." Erwin affirmed.

"And listen, I can't promise that we can give Jean a full-fledged nursery as we did with Eren, but I will make sure that we have this room set up with the essentials for a baby/toddler so that you can utilize this room anytime you need it. Just don't tell the others about it. I don't need them getting suspicious." Levi finished, making Marco burst with happiness. He had been worried about how Jean would get the privacy he needed, and now Levi would be providing it for him.

The two men left the room, and Levi returned a few moments later with multiple diapers, a pull-up, powder, lotion, wipes, and even a cushioned changing mat to lay Jean on. Marco grinned and thanked Levi before the man left them to their own devices, closing the door on his way out.

"Okay, baby, how about we give you a bath and diaper you up, hmm? Then we'll get you all cozy in some of Papa's pajamas. Doesn't thay sound nice, bub?" Jean hummed his consent sleepily, and clutched to Marco as he was once again picked up.

The freckled boy brought the other to the restroom and started the water in the tub, waiting for it to get warm before plugging the drain. He undressed Jean as he waited for the tub to fill enough, and said regressed boy giggled as Marco's hands accidentally tickled his sides. Marco chuckled quietly and kissed the boy's forehead before lifting him into the tub and settling him into the water.

He washed Jean's hair with a bottle of shampoo he had taken from his own duffel bag, then gently scrubbed the boy's body clean of dirt and grime from the day's activities. Jean was quiet, simply enjoying the warm water and his caregiver's fingers running through his hair. He decided that he liked bathtime with his Papa.

Eventually, Marco finished washing the boy and pulled the plug to the drain. He plucked the boy from the tub and wrapped a towel around him, drying Jean as best he could. Jean was nearly asleep from the comforting bath, but being jostled made him wake and whine in Marco's arms.

"Shhh, it's alright, Button, almost done. Let's get you diapered and in some jammies for bed, hmm? Just a bit more and then you can sleep."

Marco made quick work of the diaper change, though Jean began to squirm restlessly about half way through it, and he pulled out Jean's pacifier before popping it in his mouth. Then, he brought out a long-sleeved shirt and some light blue pajama pants from his duffel to change the regressed man into. Once he had finished, he scooped his boy up into his arms and carried him back to the bed, tucking him in on the side touching the wall so that he wouldn't roll himself off during the night.

Marco laid down beside Jean and turned off the beside lamp, pulling his baby closer to him and patting his bum. His fingers carded through Jean's hair, lulling the boy into a comfortable sleep, and Marco watched the crinkles on his face smooth out and disappear as he finally relaxed. He listened to Jean's even, deep breaths from behind his pacifier, and he fell began to drift off to the constant, rhythmic suckling sound of Jean's pacifier.

He kissed his baby's head one more time.

"I'm so proud of you, Button. Papa loves you so much, and I would do anything for you."

_Anything for Jean._


End file.
